plugins/mod_bosh.lua

   1 -- Prosody IM
   2 -- Copyright (C) 2008-2010 Matthew Wild
   3 -- Copyright (C) 2008-2010 Waqas Hussain
   4 --
   5 -- This project is MIT/X11 licensed. Please see the
   6 -- COPYING file in the source package for more information.
   7 --
   8
   9 module.host = "*" -- Global module
  10
  11 local hosts = _G.hosts;
  12 local lxp = require "lxp";
  13 local init_xmlhandlers = require "core.xmlhandlers"
  14 local server = require "net.server";
  15 local httpserver = require "net.httpserver";
  16 local sm = require "core.sessionmanager";
  17 local sm_destroy_session = sm.destroy_session;
  18 local new_uuid = require "util.uuid".generate;
  19 local fire_event = require "core.eventmanager".fire_event;
  20 local core_process_stanza = core_process_stanza;
  21 local st = require "util.stanza";
  22 local logger = require "util.logger";
  23 local log = logger.init("mod_bosh");
  24
  25 local xmlns_bosh = "http://jabber.org/protocol/httpbind"; -- (hard-coded into a literal in session.send)
  26 local stream_callbacks = { stream_tag = "http://jabber.org/protocol/httpbind\1body", default_ns = "jabber:client" };
  27
  28 local BOSH_DEFAULT_HOLD = tonumber(module:get_option("bosh_default_hold")) or 1;
  29 local BOSH_DEFAULT_INACTIVITY = tonumber(module:get_option("bosh_max_inactivity")) or 60;
  30 local BOSH_DEFAULT_POLLING = tonumber(module:get_option("bosh_max_polling")) or 5;
  31 local BOSH_DEFAULT_REQUESTS = tonumber(module:get_option("bosh_max_requests")) or 2;
  32 local BOSH_DEFAULT_MAXPAUSE = tonumber(module:get_option("bosh_max_pause")) or 300;
  33
  34 local default_headers = { ["Content-Type"] = "text/xml; charset=utf-8" };
  35 local session_close_reply = { headers = default_headers, body = st.stanza("body", { xmlns = xmlns_bosh, type = "terminate" }), attr = {} };
  36
  37 local t_insert, t_remove, t_concat = table.insert, table.remove, table.concat;
  38 local os_time = os.time;
  39
  40 local sessions = {};
  41 local inactive_sessions = {}; -- Sessions which have no open requests
  42
  43 -- Used to respond to idle sessions (those with waiting requests)
  44 local waiting_requests = {};
  45 function on_destroy_request(request)
  46         waiting_requests[request] = nil;
  47         local session = sessions[request.sid];
  48         if session then
  49                 local requests = session.requests;
  50                 for i,r in ipairs(requests) do
  51                         if r == request then
  52                                 t_remove(requests, i);
  53                                 break;
  54                         end
  55                 end
  56
  57                 -- If this session now has no requests open, mark it as inactive
  58                 if #requests == 0 and session.bosh_max_inactive and not inactive_sessions[session] then
  59                         inactive_sessions[session] = os_time();
  60                         (session.log or log)("debug", "BOSH session marked as inactive at %d", inactive_sessions[session]);
  61                 end
  62         end
  63 end
  64
  65 function handle_request(method, body, request)
  66         if (not body) or request.method ~= "POST" then
  67                 return "<html><body>You really don't look like a BOSH client to me... what do you want?</body></html>";
  68         end
  69         if not method then
  70                 log("debug", "Request %s suffered error %s", tostring(request.id), body);
  71                 return;
  72         end
  73         --log("debug", "Handling new request %s: %s\n----------", request.id, tostring(body));
  74         request.notopen = true;
  75         request.log = log;
  76         local parser = lxp.new(init_xmlhandlers(request, stream_callbacks), "\1");
  77
  78         parser:parse(body);
  79
  80         local session = sessions[request.sid];
  81         if session then
  82                 local r = session.requests;
  83                 log("debug", "Session %s has %d out of %d requests open", request.sid, #r, session.bosh_hold);
  84                 log("debug", "and there are %d things in the send_buffer", #session.send_buffer);
  85                 if #r > session.bosh_hold then
  86                         -- We are holding too many requests, send what's in the buffer,
  87                         log("debug", "We are holding too many requests, so...");
  88                         if #session.send_buffer > 0 then
  89                                 log("debug", "...sending what is in the buffer")
  90                                 session.send(t_concat(session.send_buffer));
  91                                 session.send_buffer = {};
  92                         else
  93                                 -- or an empty response
  94                                 log("debug", "...sending an empty response");
  95                                 session.send("");
  96                         end
  97                 elseif #session.send_buffer > 0 then
  98                         log("debug", "Session has data in the send buffer, will send now..");
  99                         local resp = t_concat(session.send_buffer);
 100                         session.send_buffer = {};
 101                         session.send(resp);
 102                 end
 103
 104                 if not request.destroyed and session.bosh_wait then
 105                         request.reply_before = os_time() + session.bosh_wait;
 106                         request.on_destroy = on_destroy_request;
 107                         waiting_requests[request] = true;
 108                 end
 109
 110                 log("debug", "Have nothing to say, so leaving request unanswered for now");
 111                 return true;
 112         end
 113 end
 114
 115
 116 local function bosh_reset_stream(session) session.notopen = true; end
 117
 118 local function bosh_close_stream(session, reason)
 119         (session.log or log)("info", "BOSH client disconnected");
 120         session_close_reply.attr.condition = reason;
 121         for _, held_request in ipairs(session.requests) do
 122                 held_request:send(session_close_reply);
 123                 held_request:destroy();
 124         end
 125         sessions[session.sid]  = nil;
 126         sm_destroy_session(session);
 127 end
 128
 129 function stream_callbacks.streamopened(request, attr)
 130         log("debug", "BOSH body open (sid: %s)", attr.sid);
 131         local sid = attr.sid
 132         if not sid then
 133                 -- New session request
 134                 request.notopen = nil; -- Signals that we accept this opening tag
 135
 136                 -- TODO: Sanity checks here (rid, to, known host, etc.)
 137                 if not hosts[attr.to] then
 138                         -- Unknown host
 139                         log("debug", "BOSH client tried to connect to unknown host: %s", tostring(attr.to));
 140                         session_close_reply.body.attr.condition = "host-unknown";
 141                         request:send(session_close_reply);
 142                         request.notopen = nil
 143                         return;
 144                 end
 145
 146                 -- New session
 147                 sid = new_uuid();
 148                 local session = { type = "c2s_unauthed", conn = {}, sid = sid, rid = tonumber(attr.rid)-1, host = attr.to, bosh_version = attr.ver, bosh_wait = attr.wait, streamid = sid,
 149                                                 bosh_hold = BOSH_DEFAULT_HOLD, bosh_max_inactive = BOSH_DEFAULT_INACTIVITY,
 150                                                 requests = { }, send_buffer = {}, reset_stream = bosh_reset_stream, close = bosh_close_stream,
 151                                                 dispatch_stanza = core_process_stanza, log = logger.init("bosh"..sid), secure = request.secure };
 152                 sessions[sid] = session;
 153
 154                 log("info", "New BOSH session, assigned it sid '%s'", sid);
 155                 local r, send_buffer = session.requests, session.send_buffer;
 156                 local response = { headers = default_headers }
 157                 function session.send(s)
 158                         --log("debug", "Sending BOSH data: %s", tostring(s));
 159                         local oldest_request = r[1];
 160                         if oldest_request then
 161                                 log("debug", "We have an open request, so sending on that");
 162                                 response.body = t_concat{"<body xmlns='http://jabber.org/protocol/httpbind' sid='", sid, "' xmlns:stream = 'http://etherx.jabber.org/streams'>", tostring(s), "</body>" };
 163                                 oldest_request:send(response);
 164                                 --log("debug", "Sent");
 165                                 if oldest_request.stayopen then
 166                                         if #r>1 then
 167                                                 -- Move front request to back
 168                                                 t_insert(r, oldest_request);
 169                                                 t_remove(r, 1);
 170                                         end
 171                                 else
 172                                         log("debug", "Destroying the request now...");
 173                                         oldest_request:destroy();
 174                                         t_remove(r, 1);
 175                                 end
 176                         elseif s ~= "" then
 177                                 log("debug", "Saved to send buffer because there are %d open requests", #r);
 178                                 -- Hmm, no requests are open :(
 179                                 t_insert(session.send_buffer, tostring(s));
 180                                 log("debug", "There are now %d things in the send_buffer", #session.send_buffer);
 181                         end
 182                 end
 183
 184                 -- Send creation response
 185
 186                 local features = st.stanza("stream:features");
 187                 fire_event("stream-features", session, features);
 188                 --xmpp:version='1.0' xmlns:xmpp='urn:xmpp:xbosh'
 189                 local response = st.stanza("body", { xmlns = xmlns_bosh,
 190                                                                         inactivity = tostring(BOSH_DEFAULT_INACTIVITY), polling = tostring(BOSH_DEFAULT_POLLING), requests = tostring(BOSH_DEFAULT_REQUESTS), hold = tostring(session.bosh_hold), maxpause = "120",
 191                                                                         sid = sid, authid = sid, ver  = '1.6', from = session.host, secure = 'true', ["xmpp:version"] = "1.0",
 192                                                                         ["xmlns:xmpp"] = "urn:xmpp:xbosh", ["xmlns:stream"] = "http://etherx.jabber.org/streams" }):add_child(features);
 193                 request:send{ headers = default_headers, body = tostring(response) };
 194
 195                 request.sid = sid;
 196                 return;
 197         end
 198
 199         local session = sessions[sid];
 200         if not session then
 201                 -- Unknown sid
 202                 log("info", "Client tried to use sid '%s' which we don't know about", sid);
 203                 request:send{ headers = default_headers, body = tostring(st.stanza("body", { xmlns = xmlns_bosh, type = "terminate", condition = "item-not-found" })) };
 204                 request.notopen = nil;
 205                 return;
 206         end
 207
 208         if session.rid then
 209                 local rid = tonumber(attr.rid);
 210                 local diff = rid - session.rid;
 211                 if diff > 1 then
 212                         session.log("warn", "rid too large (means a request was lost). Last rid: %d New rid: %s", session.rid, attr.rid);
 213                 elseif diff <= 0 then
 214                         -- Repeated, ignore
 215                         session.log("debug", "rid repeated (on request %s), ignoring: %s (diff %d)", request.id, session.rid, diff);
 216                         request.notopen = nil;
 217                         request.sid = sid;
 218                         t_insert(session.requests, request);
 219                         return;
 220                 end
 221                 session.rid = rid;
 222         end
 223
 224         if attr.type == "terminate" then
 225                 -- Client wants to end this session
 226                 session:close();
 227                 request.notopen = nil;
 228                 return;
 229         end
 230
 231         -- If session was inactive, make sure it is now marked as not
 232         if #session.requests == 0 then
 233                 (session.log or log)("debug", "BOSH client now active again at %d", os_time());
 234                 inactive_sessions[session] = nil;
 235         end
 236
 237         if session.notopen then
 238                 local features = st.stanza("stream:features");
 239                 fire_event("stream-features", session, features);
 240                 session.send(features);
 241                 session.notopen = nil;
 242         end
 243
 244         request.notopen = nil; -- Signals that we accept this opening tag
 245         t_insert(session.requests, request);
 246         request.sid = sid;
 247 end
 248
 249 function stream_callbacks.handlestanza(request, stanza)
 250         log("debug", "BOSH stanza received: %s\n", stanza:top_tag());
 251         local session = sessions[request.sid];
 252         if session then
 253                 if stanza.attr.xmlns == xmlns_bosh then
 254                         stanza.attr.xmlns = nil;
 255                 end
 256                 session.ip = request.handler.ip();
 257                 core_process_stanza(session, stanza);
 258         end
 259 end
 260
 261 local dead_sessions = {};
 262 function on_timer()
 263         -- log("debug", "Checking for requests soon to timeout...");
 264         -- Identify requests timing out within the next few seconds
 265         local now = os_time() + 3;
 266         for request in pairs(waiting_requests) do
 267                 if request.reply_before <= now then
 268                         log("debug", "%s was soon to timeout, sending empty response", request.id);
 269                         -- Send empty response to let the
 270                         -- client know we're still here
 271                         if request.conn then
 272                                 sessions[request.sid].send("");
 273                         end
 274                 end
 275         end
 276
 277         now = now - 3;
 278         local n_dead_sessions = 0;
 279         for session, inactive_since in pairs(inactive_sessions) do
 280                 if session.bosh_max_inactive then
 281                         if now - inactive_since > session.bosh_max_inactive then
 282                                 (session.log or log)("debug", "BOSH client inactive too long, destroying session at %d", now);
 283                                 sessions[session.sid]  = nil;
 284                                 inactive_sessions[session] = nil;
 285                                 n_dead_sessions = n_dead_sessions + 1;
 286                                 dead_sessions[n_dead_sessions] = session;
 287                         end
 288                 else
 289                         inactive_sessions[session] = nil;
 290                 end
 291         end
 292
 293         for i=1,n_dead_sessions do
 294                 local session = dead_sessions[i];
 295                 dead_sessions[i] = nil;
 296                 sm_destroy_session(session, "BOSH client silent for over "..session.bosh_max_inactive.." seconds");
 297         end
 298 end
 299
 300 local ports = module:get_option("bosh_ports") or { 5280 };
 301 httpserver.new_from_config(ports, handle_request, { base = "http-bind" });
 302
 303 server.addtimer(on_timer);